Fuel control device for fuel injection pump governors

ABSTRACT

A control device for turbo charged diesel engines for varying the position of the fuel injection pump governor full load stop to provide excess fuel during engine cranking and to limit full load fuel delivery during acceleration and low speed operation. The device includes a cylinder, one end of which is connected to a source of engine lubricating oil and the other end of which is subjected to engine manifold pressure. An oil pressure responsive piston in the cylinder carries therewithin a smaller manifold pressure responsive piston which is connected directly to the governor full load stop to control the stop position. The pistons are each spring-loaded against the force of their respective actuating fluids whereupon an absence of oil pressure will produce an excess fuel position of the full load stop, and a drop in manifold pressure during engine operation will result in a fuel limiting position of the full load stop.

United States Patent [151 3,707,144

Galis et al. [4 1 Dec. 26, 1972 [54] FUEL CONTROL DEVICE FOR FUEL INJECTION PUMP GOVERNORS Primary ExaminerLaurence M. Goodridge Assistant Examiner-Ronald B. Cox

[72] Inventors: Leon A. Galis, Ludlow, Mass;

Donald E. Valentine, Brookfield, Attorney-Hows & Howson 57 ABSTRACT [73] Asslgnee: fi g Spnng' A control device for turbo charged diesel engines for varying the position of the fuel injection pump gover- [22] Filed: July 1, 1971 nor full load stop to provide excess fuel during engine cranking and to limit full load fuel delivery during ac- [211 App! 158394 celeration and low speed operation. The device includes a cylinder, one end of which is connected to a I [52] 11.8. Cl....l23/l79 L, 123/140 MP, 123/140 FL, source of engine lubricating oil and the other end of 123/140 R, 123/179 G which is subjected to engine'manifold pressure. An oil [51] Int. Cl. ..F02n 12/00, F02d l/04 pressure responsive piston in the cylinder carries Field of Search 140 MP,140 therewithin a smaller manifold pressure responsive 123/140 179 G piston which is connected directly to the governor full load stop to control the stop position. The pistons are [56] R f r n Ci d each spring-loaded against the force of their respective actuating fluids whereupon an absence of oil pres- UNITED STATES PATENTS sure will' produce an excess fuel position of the full 3,103,211 9/1963 Cameron "123/140 load Stop, and a drop in manifold pressure during en- 3,311,102 3/1967 Voigt gine operation will result in a fuel limiting position of 2,940,436 6/1960 De Claire the full load stop. I 3,149,619 9/1964 Whalen 2,233,035 2/1941 Schweizer ..l23/l40 11 Claims, 6 Drawing Figures /3' /26 T 21 e 2 STAR N 8 64 /00-i 52 2\ 0a w 6 94 //0 20 //2 -6 a4 64 //0 5.4 a as awn/62L, Z

PATENTEDUEBZB 1912 SHEET 1 OF 2 FIG].

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IV yr I INVENTORSZ LEON A. GALIS DONALD E. VALENTINE MW 434 STARTING J POSITION F IG. 2.

ATTYS.

PATENTED DEC 2 6 I972 SHEET 2 OF 2 I STARTING POSITION POSITION l l-vNORMAL RUN POSITION INVENTORsI LEON A. GALIS DONALD E. VALENTINE WJW F LLIMIT POSITION ATTYS FUEL CONTROL DEVICE FOR FUEL INJECTION PUMP GOVERNORS The present invention relates generally to fuel injection pumps for compression ignition internal combustion engines and relates more particularly to a fuel control device for turbocharged diesel engine fuel injection pump governors.

The need for supplying excess fuel to compression ignition fuel injection engines during starting is well known and many devices both of the automatic and manually operated type have been developed for this purpose. For example, in U. S. Pat. No. 3,3ll,ll which is assigned with the present application to a common assignee, a device is shown for automatically providing excess fuel during engine cranking. It has in addition been recognized that in turbocharged diesel engines, wherein the intake manifold is pressurized by an exhaust gas driven blower, that full load fuel delivery should be limited during engine acceleration to prevent excess fuel delivery and consequent smoking of the engine.

In the present invention, a single control device is provided which automatically establishes an excess fuel position of the governor full load stop during engine cranking, and in addition serves to establish a fuel limiting position of the governor full load stop during acceleration or low speed full load operation when the engine turbocharger is unable to maintain the required air delivery to the cylinders.

The present device in brief comprises a cylinder mounted adjacent the fuel injection pump governor full load stop having a first piston which is positioned against a spring force by the pressure of the engine lubricating oil which is admitted to one end of the cylinder. The first piston includes a cylindrical bore which serves as the cylinder for a second piston which is spring loaded away from the first piston and which is positioned by the intake manifold pressure admitted to the opposite end of the cylinder from the lubricating oil. The second piston, which has a limited range of travel within the first piston, is connected directly to the full load stop to establish the stop fuel control position.

During engine cranking, the lubricating oil pressure will be too low to actuate the first piston which along with the captive second piston and attached full load stop will be maintained by the spring force in an excess fuel position. After the engine has started, the first piston will be moved to its normal operating position by the lubricating oil pressure and the device will thereafter during continued operation of the engine function only to adjust the full load stop in accordance with changes in engine intake manifold pressure. Under normal operating conditions, the intake manifold pressure will be sufficient to compress the spring between the two pistons thus establishing a normal full load stop position. Upon drop in intake manifold pressure, such as during acceleration or engine lugging at low speed, the manifold pressure will be insufficient to hold the second piston against the spring force, and the piston and full load stop will thus move to a fuel limiting position until the manifold pressure is restored to its normal range.

It is accordingly a first object of the present invention to provide a fuel control device for a fuel injection pump governor which will serve both to provide excess fuel during engine cranking and to limit fuel delivery during engine acceleration or low speed engine lugging to prevent excess fuel delivery and engine smoking.

A further object of the invention is to provide a fuel control device as described whichpermits an excess fuel delivery for a sufficient time during the engine starting interval to assure adequate fuel delivery while the engine is cold and to'prevent stalling of the engine in the event of a momentary misfire.

Another object is toprovide a fuel control device as described of a relatively simple, compact construction which can readily be mounted within the governor housing of a fuel injection pump governor.

Additional objects and advantages of the invention will be more readily apparent from the following detailed description of embodiments thereof when taken together with the accompanying drawings wherein: Y

FIG. 1 is a side elevational view partly broken away and partly in section showing a fuel injection pump governor having a fuel control device in accordance with the present invention mounted therein for control of the full load stop position;

FIG. 2 is an enlarged sectional view taken along line 2-2 ofFIG. 1;

FIG. 3 is a sectional .view taken along line 3-3 of FIG. 2 showing the interior details of the fuel control device in the engine starting position;

FIG. 4 is a view similar to FIG. 3 showing the device in the normal operating position;

FIG. 5 is a view similar to FIGS. 3 and 4 showing the device in a fuel limiting position; and

FIG. 6 is a fragmentary sectional view taken along line 6-6 of FIG. 4.

Referring to the drawings and particularly FIG. 1 thereof, a conventional type of fuel injection pump governor generally designated 10 having a governor housing 12 is shown attached to an adjacent fuel injection pump housing 14, only a small portion of which appears in FIG. 1. The governor includes a governor shaft 16 driven in rotation by the fuel injection pump and on which is mounted the centrifugal weights 18 which control the axial position of a spring loaded linkage 20 in accordance with the speed of rotation of the engine. A fulcrum lever 22 is coupled to the linkage 20 by means of the pin and slot connection 24 and at its upper end is pivotally connected by means of arm 24 to the fuel control rod 26, the movement of which controls the fuel output of the injection pump. The lower end of the fulcrum lever 22 is operatively secured by pin connection 28 to the trunnion lever 30 on the operating lever shaft 32.

With the linkage 20 being positioned in accordance with engine speed, and the operating lever shaft 32 being rotated by the operating lever in accordance with the throttle setting, it will be apparent that the position of the fuel control rod 26 will be determined both by the throttle setting and the engine speed. In addition, to prevent the fuel injection pump from delivering an excess quantity of fuel such as at full load, a full load stop 34 is provided which is engaged by the adjustable full load cam 36 on the upper end of the fulcrum lever as indicated in broken lines to limit the fuel increase setting of the fuel control rod. To permit the full load stop 34 to override the setting of the fulcrum lever which would otherwise result, the trunnion lever 30 is spring loaded in a well known manner. i The governor structure thus far briefly described is as indicated completely conventional and isdisclosed to provide a setting for the present fuel control device. A more complete description of the structure and operation of this type of governor and pump is .set forth in the above U.S. Pat. No. 3,311,101 which ishereby incorporated by reference. I

The present invention comprises a fuel control device generally designated 40 which serves to support and determine the position of the, full load stop34v in device 40 includesa fuel control housing 42 located adjacent the full load stop 34 having ears 44 one ach side thereof through which bolts 46 pass to securethe housing to lugs extending from the governor housing 12. The fuel control housingincludesa cylinder portion 48 having a bore 50 extending thereinto from the'end of the fuel control housing opposite the full load stop 34. A disc shaped stop element 52 is fitted within a slightly enlarged portion 54 of the bore at the open end of the bore to form a substantially cylindrical chamber 56 within the housing. The element '52 is secured in position by means of a retainer bracket 58 which in turn is held in place by the bolts 46 as shown most clearly in FIG. 2.

Slidably disposed within the chamber 56 is an excess fuel piston 60 having a peripheral seal ring 62 in engagement with the bore walls. The piston 60 is spring loaded toward the stop element 52 by a coil spring 64 seated in an annular groove 66 in the end of the housing at one end, and bearing against theinternal spring washer 68 set in a groove in an internal bore 70 of the piston.

The piston 60 is moved against the force of the spring 64 by the pressure of engine lubricating oil which is introduced into the chamber 56 through a conduit 72 which as shown in FIG. 2 extends into a bore 74 in the base of the fuel control housing 42Q'The conduit '72 opens into a chamber 76 in the housing from which the lubricating oil passes through the small passage 78 into A small passage 94 is provided in the stop disc 52- to facilitate the draining of lubricating oil from the chamber 56 particularly upon stopping of the engine. Although the hole appears from the drawings to be blocked by the bracket 58. the pressurized oil will pass between the bracket and the element 52 and drain into the governor housing. This arrangement prevents a spraying .of the oil when the governor is operated, for example during servicing, with the top cover 96 of the governor housing removed.

A manifold pressure. piston. 98 is slidably disposed within the bore 70 of the excess fuel piston 60 and includes a .piston seal-ring 100 in engagement with the bore walls. The'piston 98 includes an integral coaxial piston rod including a cylindrical portion102 which slidablypasses through a bore 104 in the end of the fuel control housing, and a threaded outer endportion 106 which passes through a similarly threaded bore 108 in is provided to secure the piston-full load stop relationpiston is in the extreme right-hand position against the stop element 52. As shown in FIG. 3, a shoulder 80 of the piston engages a seal ring 82 on a shoulder 84 of the stop element 52 and establishes an annular chamber 86 into which the lubricating oil initially is passed from the passage 78 upon thestarting of the engineJThe seal .ring 82 prevents the lubricating oil pressure from acting against the end face 88 of the piston until the piston has including the wall 88 thereof and will rapidly move the piston to the left into the position shown'in FIGS. 4 and ship in the established position.

The desired vertical alignment of the full load stop 34 is maintained by a cylindrical guide 114 extending transversely to the full load stop and received in slidable relation within the bore 116 in the lower portion of the fuel controlihousing. The guide shaft 114 also serves to prevent rotation of the full load stop, both during operation of the device and during rotational adjustment of the piston rod.

The travel of the piston 98 within the bore 70 of piston.60 isrestricted inone direction by the spring washers 68, and in the other direction by the end wall 88 of the piston 60. A coil spring ll'8is mounted in compression within the chamber 120 formed between the piston '98 and the end 88 of piston to urge the piston 98 toward the spring washer 68. To permit movement of the piston 98 against the spring force toward the end of the excess fuel piston, a coaxial venting bore 122 is provided in the piston rod to vent the chamber 120 into the governor housing.

Means are provided for connecting the left end of chamber 56 with the engine intake manifold whereby the piston 98 will be positioned within the bore of thepiston 60 by the force of the mainfold pressure acting in opposition to the forceof spring 118. For this purpose, a cylindrical upwardly extending portion 124 of the housing 42 is provided with a vertical passage 126 which opensinto an annular groove 128 at the end of the bore 50 adjacentthe shoulder 92. The housing portion 124 extends into the bore 130 of a boss 132 on the top of the housing cover 96 and is sealed with respect thereto by the seal ring 134. As shown in FIG.

- 1, the outer end of the bore 130 is threaded to receive a suitable conduit (not shown) leading to the engine intake manifold. To permit communication of the 5 wherein the forward edge of the piston-engages the annular shoulder 92 of the fuel control housing.

passage 126 with the ,bore 50 when the excess fuel piston 60 is in the position shown in FIGS. 4 and 5 against shoulder 92, a slot 136 is provided in the piston end 90 as shown for example in FIG. 6.

For operation of the device, the conduit 72 is connected with the engine lubricating oil distribution system and the bore 130 is provided with a suitable conduit connection to the engine intake manifold. The full load stop is adjusted by means of its threaded connection with the end portion 106 of the piston rod to properly limit fuel delivery under normal operating conditions with the pistons in the position shown in FIG. 4. The device then functions automatically to provide excess fuel during starting and to limit full load fuel delivery during acceleration and low speed engine operation.

Summarizing the operation, during starting, the lubricating oil pressure and manifold pressure will be so low as to have no effect on the excess fuel piston or the manifold pressure piston and the pistons will assume the positions shown in FIG. 3 under the. influence of their respective springs 64 and 118. This results in a full load stop starting position which permits the full load cam 36 to move into the position shown in broken lines in FIGS. 1 and 3 as the operating lever is advanced to its maximum fuel position by the operator. This will move the fuel control rod 26 toward the right as viewed in FIG. 1 which serves to increase the fuel'delivery of the fuel injection pump. As described above, the movement of the excess fuel piston under the influence of the lubricating oil pressure is delayed by means of the engagement of the piston with the seal ring 82 until the engine has started and reached a speed sufficient to generate a substantial lubricating oil pressure. When this condition is reached, the excess fuel piston will be quickly moved to the engine operating position shown in FIGS. 4 and 5 and will be maintained in that position until the engine is stopped.

As shown in FIG. 4, during the normal operation of the engine, the intake manifold pressure will be sufficiently high to move the manifold pressure piston to the right against the force of spring 118 into engagement with the end wall 88 of the excess fuel piston. The device will maintain the full load stop in this position under most operating conditions.

During acceleration of the engine and during low speed full load operation, however, the intake manifold pressure will be lower than necessary to provide sufficient combustion air for the fuel which normally would be delivered by the pump. To prevent excess fuel delivery and the consequent smoking of the engine, the fuel control device automatically moves the full load stop to a fuel limiting position as shown in FIG. 5. As the manifold pressure drops, the spring 118 overcomes the force exerted on the piston 98 by the manifold pressure, moving the piston to the left into engagement with the spring washer 68. The fuel limiting position of the full load stop shown in FIG. 5 by limiting the advance of the fulcrum lever full load cam consequently reduces the fuel delivery to the engine. When the manifold pressure again returns to its usual level, it moves the piston 98 to the right against the force of the spring 118 and returns the full load stop to the normal run position of FIG. 4.

In a preferred embodiment of the invention, the fluid pressures required to actuate the pistons are about psi for the engine lubricating oil pressure and 5 to 7 inches of mercury for the intake manifold pressure. These values are only examples and it will be obvious that other suitable values for these pressures could be employed.

Manifestly, changes in details can be effected by those skilled in the art without departing from the spirit and scope of the invention.

We claim 1. A fuel control device for diesel engine fuel injection pump governors for positioning the governor full load stop in accordance with engine operating conditions comprising, cylinder disposed adjacent the governor full load stop, a first piston in said cylinder, means for introducing an engine pressurized fluid into said cylinder at one side of said piston, spring means for biasing said piston against said pressurized fluid, a bore in said first piston, a second piston slidably disposed within said bore of said first piston and having a piston rod extending from said cylinder, said piston rod being connected with the full load stop to establish the operating position thereof, means for introducing engine intake manifold pressure into said cylinder at the opposite side of said first piston form said engine pressurized fluid, means for limiting the axial movement of said second piston within said first piston, and spring means biasing said second piston against the intake manifold pressure.

2. The invention as claimedin claim 1 including means adapted to delay movement of said first piston under the influence of said engine pressurized fluid until said fluid has reached a predetermined pressure.

3. The invention as claimed in claim 1 wherein said engine pressurized fluid comprises the engine lubricating oil.

4. The invention as claimed in claim 1 including an axial bore in said piston rod for venting the bore of said first piston between said first and second pistons.

5. The invention as claimed in claim 1 including means for adjusting the axial position of the governor full load stop with respect to said piston rod.

6. In a diesel engine fuel injection pump governor having a full load stop adapted to coact with the governor throttle linkage to limit fuel input to the engine, the improve-ment comprising a fuel control device for positioning the full load stop to provide excess fuel delivery during engine cranking and limited fuel delivery during acceleration and low speed operation, said fuel control device comprising a cylinder disposed adjacent the full load stop with the cylinder axis perpendicular to the full load stop, a first piston slidably disposed in said cylinder, means for introducing an engine pressurized fluid into said cylinder at one side of said piston, a spring on the opposite side of said piston for biasing said piston against said pressurized fluid, a bore in said first piston, a second piston slidably disposed within said bore of said first piston, means for limiting the axial movement of said second piston within said first piston bore, a piston rod connected with said second piston and extending coaxially therefrom through said cylinder, said piston rod being connected to the full load stop to establish the operating position thereof in accordance with the engine operating condition, an axial bore in said piston rod for venting the bore of said first piston between said first and second pistons, means for connecting said cylinder on the opposite side of said first piston from said engine pressurized fluid with the engine intake manifold to maintain the manifold pressure therein, and a spring between said first and second pistons for biasing said second piston against the intake manifold pressure, said first piston moving from an excess fuel position to a normal operating position upon starting of the engine, said second piston moving to a fuel limiting position upon the falling of the intake manifold pressure below a predetermined level.

7. The invention as claimed in claim 6 including means adapted to delay movement of said first piston under the influence of said engine pressurized fluid until said fluid has reached a predetermined pressure.

8. The invention as claimed in claim 7 wherein said latter means comprises means restricting the area of said first piston exposed to said pressurized fluid until said fluid has reached a predetermined pressure.

9. The invention as claimed in claim 6 wherein said engine pressurized fluid comprises the engine lubricatin oil.

10. The invention as claimed in claim 6 including means for adjusting the axial position of the full load stop with respect to said piston rod.

11. The invention as claimed in claim 10 wherein said piston rod is threadedly connected with the full load stop.

F l l t 

1. A fuel control device for diesel engine fuel injection pump governors for positioning the governor full load stop in accordance with engine operating conditions comprising, cylinder disposed adjacent the governor full load stop, a first piston in said cylinder, means for introducing an engine pressurized fluid into said cylinder at one side of said piston, spring means for biasing said piston against said pressurized fluid, a bore in said first piston, a second piston slidably disposed within said bore of said first piston and having a piston rod extending from said cylinder, said piston rod being connected with the full load stop to establish the operating position thereof, means for introducing engine intake manifold pressure into said cylinder at the opposite side of said first piston form said engine pressurized fluid, means for limiting the axial movement of said second piston within said first piston, and spring means biasing said second piston against the intake manifold pressure.
 2. The invention as claimed in claim 1 including means adapted to delay movement of said first piston under the influence of said engine pressurized fluid until said fluid has reached a predetermined pressure.
 3. The invention as claimed in claim 1 wherein said engine pressurized fluid comprises the engine lubricating oil.
 4. The invention as claimed in claim 1 including an axial bore in said piston rod for venting the bore of said first piston between said first and second pistons.
 5. The invention as claimed in claim 1 including means for adjusting the axial position of the governor full load stop with respect to said piston rod.
 6. In a diesel engine fuel injection pump governor having a full load stop adapted to coact with the governor throttle linkage to limit fuel input to the engine, the improve-ment comprising a fuel control device for positioning the full load stop to provide excess fuel delivery during engine cranking and limited fuel delivery during acceleration and low speed operation, said fuel control device comprising a cylinder disposed adjacent the full load stop with the cylinder axis perpendicular to the full load stop, a first piston slidably disposed in said cylinder, means for introducing an engine pressurized fluid into said cylinder at one side of said piston, a spring on the opposite side of said piston for biasing said piston against said pressurized fluid, a bore in said first piston, a second piston slidably disposed within said bore of said first piston, means for limiting the axial movement of said second piston within said first piston bore, a piston rod connected with said second piston and extending coaxially there-from through said cylinder, said piston rod being connected to the full load stop to establish the operating position thereof in accordance with the engine operating condition, an axial bore in said piston rod for venting the bore of said first piston between said first and second pistons, means for connecting said cylinder on the opposite side of said first piston from said engine pressurized fluid with the engine intake manifold to maintain the manifold pressure therein, and a spring between said first and second pistons for biasing said second piston against the intake manifold pressure, said first piston moving from an excess fuel position to a normal operating position upon starting of the engine, said second piston moving to a fuel limiting position upon the falling of the intake manifold pressure below a predetermined level.
 7. The invention as claimed in claim 6 including means adapted to delay movement of said first piston under the influence of said engine pressurized fluid until said fluid has reached a predetermined pressure.
 8. The invention as claimed in claim 7 wherein said latter means comprises means restricting the area of said first piston exposed to said pressurized fluid until said fluid has reached a predetermined pressure.
 9. The invention as claimed in claim 6 wherein said engine pressurized fluid comprises the engine lubricating oil.
 10. The invention as claimed in claim 6 including means for adjusting the axial position of the full load stop with respect to said piston rod.
 11. The invention as claimed in claim 10 wherein said piston rod is threadedly connected with the full load stop. 